Performance Analysis of 11KV Industrial Distribution ... · Performance Analysis of 11KV Industrial Distribution Feeder ... Capacitor banks and voltage regulators are installed to

16 Puneet Chawla

International Journal of Electronics, Electrical and Computational System

IJEECS

ISSN 2348-117X

Volume 5, Issue 9

September 2016

Performance Analysis of 11KV Industrial Distribution Feeder

with Calculation of Capacitor Bank

Puneet Chawla

Astt Prof., Electrical Engg. Dept.,

Ch. Devi Lal State Institute of Engg. & Tech., Panniwala Mota (Sirsa)

ABSTRACT: Due to wide need of electrical power supply day-to-day in all fields of human activities, there is a need of

increased generation capacity and thus construction of new electric power stations are required. Thus, the need of

growing power generation and utilization, there is a requirement to expand continuously electric machines

manufacturing industry applying modern techniques. However, in support to the effective utilization of this high amount

of power generation using the very large size machines at power station, sub-transmission and distribution systems

constitute the link between electricity utilities and consumers. Efficient functioning of all these segments of the electricity

utility such as power generation, sub-transmission and distribution sectors are essential to sustain the growth of the

power sector and the economy of the country. But the distribution sector plays a vital role for the effective consumption

of electrical power with economy to provide electrical energy at a suitable prize and at a minimum voltage drop to

reduce the voltage regulation. This is based on the effective operating of State Electricity Boards in an economical way

at minimum voltage drop and reduce the regulation of voltage. The present calculation work had an attempt for the

comprehensive designing for the existing distribution network (11kV Industrial Feeder) alongwith the capacitor bank

size and design with an objective to minimize the investment cost, total power losses, reliability indices for a study

timeframe in the above distribution feeder. The voltage drop and power loss before and after installing the capacitors

were compared in the work. The result showed better voltage profiles and power losses in the distribution system had

been improved in this calculative attempt.

Keywords: Capacitor, Industrial, Machines, Regulation, Techniques.

1. INTRODUCTION ABOUT FEEDERS

Energy is the primary and most universal measure of all kinds of works by human beings and nature. Most

people use the word energy for input to their bodies or to the machines and thus think about crude fuels and

electric power. In the past, the consumption of electricity is prime motto, as it is available in lot with a

capacity to do work, but as the time spent, now time is to conserve the electricity not to consume the electrical

energy. In fact, it has become essential ingredient for improving the quality of life and its absence is

associated with poverty and poor quality of life. The per capita income of U.S.A is about 50 times more than

per capita income of India, and so also is the per capita energy consumption. The per capita energy

consumption in U.S.A is about 8000 KWh per year whereas the per capita energy consumption in India is 150

KWh. U.S.A with 7% of world’s population consumes 32% of the total energy consumed in the world,

whereas India, a developing country with 20% of the world’s population consumes only 1%of the total energy

consumed in the world. Sub-transmission and distribution systems constitute the link between electricity

utilities and consumers. Efficient functioning of these segments of the electricity utility is very useful for the

growth of the power sector and the economy of the country. Thus, the distribution sectors require economical

system to provide electrical energy at a suitable prize and at a minimum voltage drop to reduce the voltage

regulation. So, we require the economical way to provide the electrical energy by State Electricity Boards to

various consumers at minimum voltage drop and reduce the regulation of voltage. The feeder voltage and

feeder current are two constraints which should be within the standard range. As the distribution network is

located far away from the sources of power generation and the other infrastructure of electrical power system.

So, there will be voltage drop, line losses and system reliability comes into the act. Long distance to supply

loads causes a significant amount of voltage drop across the distribution lines. Capacitor banks and voltage

regulators are installed to decrease the voltage drop. The long distance also increases the probability of

occurrence of a failure and this reduces the network reliability. The present work emphasis the comprehensive

designing for the existing distribution network with an objective to minimize the investment cost, line losses,

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September 2016

reliability indices for a study timeframe, distance of load and load growth. The allocation and resizing of

conductors and calculation of size of the capacitor bank in the present research paper, make importance of

selecting a proper optimization method, by considering different parameters, such as power factor of system,

feeder voltage and current, temperature of surroundings and of the conductors etc.

2. ELECTRICITY SECTOR IN INDIA

The electricity sector in India is predominantly controlled by government sector entities via central public

sector corporation, such as National Thermal Power Corporation (NTPC), National Hydroelectric Power

Corporation (NHPC) and various state level corporations (state electricity boards-SEBs). India is world’s’ 3rd

largest country, accounting for 4.8% for global energy consumption in the year 2013. Due to India’s economic

rise, the demand for energy has grown at an average of 3.6% per annum over the last 30 years. About 76% of

the electricity consumed in India is generated by thermal power plants, 21% by hydroelectric power plants and

4% by the nuclear power plants. The details are as under in table 1 [1]. The total installed capacity in India is

305.554GW till 31.08.2016.

Sr. No. Generation Total capacity till 31.08.2016

1. Thermal Power 212.568 GW

2. Hydro Power 42.968 GW

3. Nuclear Power 20 nuclear reactors in operation, generating 5.780GW

4. Renewable Power 44236.92 MW

Table 1: Electricity Sector in India [1]

3. PUNJAB STATE POWER SECTOR

Punjab State Electricity Board (PSEB), in its present form came into existence under Section 5 of the

Electricity (Supply) Act-1948 on May 2, 1967 after the reorganization of the State for generation,

transmission and distribution of electricity in Punjab. The installed capacity of electricity in the State

increased from 3524 MW to 1996-97 to 46409.38 MU in 2013-14 (4285.94 MU Hydel + 16306.27 MU

Thermal). The installed capacity generation in Punjab is as shown in table 2 [2]. Sr. No.

Name of Project Detail of Power machines with installed capacity

(MW)

Share of Punjab (MW)

Generation during 2013-14 (MU)

Generation upto 31.08.2016

(MU)

1. OWN PROJECTS

a) Hydro Electric Projects

1. Shanan PH 4x15+1x50=110.00 110 355.87 355.87

2. UBDC 3x15+3x15.45=91.35 91.35 361.624 361.624

3. Anandpur Sahib 4x33.5=134.00 314 735.00 735.00

4. RSDHEP 4x150=600 452.4 1575.89 1575.89

5. Mukerian 6x15+6x19.5=207.0 207 1246.74 1246.74

6. Nadampur Micro 2x0.4=0.80 0.8 10.82 10.82

7. Daudhar Micro 3x0.5=1.50 1.5

8. Rohti Micro 2x0.4=0.80. 0.8

9. Thuhi Micro 2x0.4=0.80 0.8

10. GGSSTP Ropar (Micro) 1.7

Total 1000.35 4285.94 4285.94

b) Thermal Projects

1. GNDTP Bathinda 4x110=440.00 440 1635.46 2487.633

2. GGSSTP, Ropar 6x210=1260.00 1260 8805.87 9984.65

3. GHTP, Lehra Mohabat (Bathinda) 2x210+2x250=920.00 920 6664.994 6664.994

4. RSTP, Jalkheri 1x10=10.00

. Total 2630 16306.27 16306.27

Total (a + b) 3630 20592.21 20592.21

2. Share from BBMM Projects 1161.00 4382.31 4382.31

3. Share from Central Sector Projects 3071 20785.71 20785.71

4. PEDA & Industrial Captive Plants

installed in State

997 649.15 649.15

Grand Total (1+2+3+4) 8859.00 46409.38 46409.38

Table 2: Installed capacity generation in Punjab [2]

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4. LITREATURE SEARCH

Transmission & Distribution (T&D) losses represent a significant proportion of electricity losses in both

developing and developed countries. The major portion of occurrence of T&D losses is the distribution

systems of the states, which makes the gap large between the demand and supply of the electricity. Electric

power providers have a duty to ensure that the consumers are always supplied with the required voltage level.

However, the consumers at the extreme end of the feeders have been experiencing low voltage levels in

somewhere all the countries. This is due to, in most cases, voltage drops is a major concern in low voltage

distribution systems and not very particular about voltage drop in the high voltage sides leaving it unattended.

Ritula Thakur et al in [3] presented a paper analysing and designing with the observation that the existing

feeder is to be operated on 0.88power factor at a temperature range of conductor at 200C, however it is come

to notice while analysing that the conductor size can be augmentated with 65mm2

(DOG) and 48mm2

(RACCOON) to the use of 80mm2 (LEOPARD) and 50mm

2 (OTTER) for reduction of voltage drop in feeder,

due to its better current carrying capacity of 375A in comparison of 324A of 65mm2 conductor and same

linear coefficient of temperature rise and modulus of elasticity, as observed from the diagram obtained after

analysis. But the weight of 80mm2 conductor is 27.9mm

2 increased, which can be supported by the existing

structures installed in the feeder area.

Soloman Nunoo et al in [4] presented a paper analysing the causes and effects of voltage drop on the 11KV

GMC sub-transmission feeder in Tarkwa, Ghana. Studies showed that the voltage drop, total impedance,

percentage efficiency and percentage regulation on the feeder are 944V, 4.56Ω, 91.79% and 8.94%

respectively. Which all are beyond the acceptable limits. From the result, it is also realised that the causes of

voltage drop on the feeder was mainly due to high impedance level as compared to the permissible value and

this high impedance is caused by:-

(i) Poor jointing and terminations.

(ii) Use of undersized conductors.

(iii) Use of different types of conductor materials

(iv) Hot Spots etc.

The work concluded by proposing a number of solutions as well. In this paper, it was observed that the outage

level of GMC Feeder is currently high of which stands at an average of ten times with a least duration of 10

minutes. These outages are mostly caused by:

(i) Over-grown of vegetation very close to the line, which comes in contact to the feeder in the events of

strong winds.

(ii) Over-sagged conductors as a result of long spans between poles and

(iii) Obsolete headgear accessories, equipment and bent conductors.

Vujosevic, L. et al in [5] presented a paper estimating that the voltage drop in radial distribution networks can

be applied for all voltage levels, therefore it was indicated in the work that in distribution system, voltage drop

is the main indicator of power quality and it has a significant influence at normal working regime of electrical

appliances, especially motors. This work was mainly focused on low voltage distribution system. C.G. Carter-

Brown et al in [6] presented a paper, in which a model is developed to calculate MV and LV voltage and

voltage drop limits based on differential network-load combinations. The result of the model are suitable

accurate for the calculation of guidelines for optimum voltage drop limits. Medium and low voltage (MV and

LV) electricity distribution networks should supply customers at voltages within ranges that allow the

efficient and economic operation of equipment and appliances. The permitted voltage variation is usually

defined in regulations. Voltage variation is a key constraint in electricity weak networks and voltage

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September 2016

management is applied to compensate for the voltage drop in the impedance of the distribution feeders

through improving the load power factors or changing the effective ratio of the transformers and voltage

regulators. C.G. Carter-Brown et al in [7 & 8] presented a paper, which comprises of the various factors for

voltage drop apportionment or voltage variation management in Eksom’s distribution networks, in which

voltage regulation is a term used to describe the variation of voltage. This paper, which consists of optimal

voltage regulation limits and voltage drop apportionment in the distribution systems, in which the planner/

designer of a future network assumes the network will be operated in a reasonable manner (voltage control,

tap settings, balanced loads and appropriate configuration of normally open points) and apportions the

allowable voltage variation between the MV and LV terminals. Sarang Pande et al in [9] presented a paper, in

which a method for energy losses calculation is presented. This paper demonstrates the capability of Load

factor and load loss factor to calculate the power losses of the network. The results obtained can be used for

financial loss calculation and can be presented to regulate the tariff determination process. The technical

losses are the losses occurred in the electrical elements during of transmission of energy from source to

consumer and mainly comprises of ohmic and iron losses. J.J. Grainger et al in [10] presented a paper, in

which it was presented an analytical method which is easy to understand and gives detailed mathematical

model to conduct the reactive energy compensation in an optimal way i.e. to have less power and energy

losses. Indeed, this method allows the electrical energy suppliers to choose either to optimise either capacitor

location or size or both of them at the same time. Nevertheless, owing to the fact that this paper has defined

the power and energy loss reduction due to a given capacitor as dependent only on the powers of those

located. The three capacitors size and location optimization problem is considered where the load factor Lf is

equal to 0.45. Technical Application paper of Asea Brown Baveri (ABB) et al in [11] presented a technical

paper, in which it was presented that in electrical plants, the loads draw from the network electrical power

(active) as power supply or convert it into another form of energy or into mechanical output. To get this, it is

often necessary that the load exchanges with the network the reactive energy mainly of inductive type. This

energy contributes to increase the total power flowing through the in the electrical network, from the

generators, all along the conductors, to the users. To smooth such negative effect, the power factor correction

of the electrical plants is carried out. The power factor correction obtained by using capacitor banks to

generate locally electrical energy necessary to transfer of electrical useful power, allows a better and more

rational technical-economical management of the plants. According to the location modalities of the

capacitors the main methods of power factor correction are: distributed power factor correction, group power

factor correction, centralized power factor correction, combined power factor correction, automatic power

factor correction. Technical report of Nokian Capacitors et al in [12] presented a technical report, in which it

was presented that in addition to active power most electrical devices also demand reactive power. If this

reactive power is not provided by the capacitors in the immediate vicinity, it must be transmitted via the

distribution system. In this case, the influence of the reactive power on the total current must be taken account

when designing the system and this can lead to a need for large transformer and cables & transmission lines

than as required. Moreover, transmission of reactive power causes additional energy losses. By means of

reactive power compensation the amount of reactive power has only little significance in dimensioning the

system and on transmission losses. The most economical way of producing reactive power required most

electrical devices is by use of capacitors. Capacitors reduce network losses and voltage drop, and the

transmission of reactive power is avoided. By series capacitor bank, voltage may be raised to a desired level.

Parallel capacitor banks can be used for individual, group or central compensation.

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5. VOLTAGE DROP CALCULATION OF URBAN DISTRIBUTION FEEDER (11KV

INDUSTRIAL FEEDER)

The single-line diagram of the 11kV Industrial Feeder is obtained from Punjab State Power Cooperation Ltd.

is available at fig. no. 1 and hereby re-drawn in fig. no. 2 in the ETAP software

Fig.1 Rough Sketch of 11kV Industrial Feeder of Abohar Subdivision

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Fig. 2 Single Line diagram of 11kV Industrial Feeder redrawn in ETAP

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Data of Feeder

The data obtained from State Electricity Board of Subdivision is as under as shown in table no. 3 [13].

Sr. No. From- To ACSR size kVA Km Factor Voltage drop

1 AB 48mm2 7829 0.185 0.0490 70.970

2. BC 48mm2 7729 0.064 0.0490 24.238

3. CD 48mm2 7629 0.398 0.0490 148.781

4. DE 48mm2 7466 0.424 0.0490 155.114

5. EF 48mm2 7366 0.112 0.0490 40.425

6. FG 48mm2 7266 0.186 0.0490 66.222

7. GH 48mm2 7166 0.140 0.0490 49.159

8. HI 48mm2 7066 0.053 0.0490 18.350

9. IJ 48mm2 6966 0.026 0.0490 8.875

10. JK 48mm2 5866 0.125 0.0490 35.929

11. KL 48mm2 5766 0.014 0.0490 3.955

12. LM 48mm2 5466 0.085 0.0490 22.766

13. MN 48mm2 5166 0.035 0.0490 8.860

14. NO 48mm2 5066 0.030 0.0490 7.447

15. OP 48mm2 4966 0.036 0.0490 8.760

16. PQ 48mm2 4866 0.034 0.0490 8.107

17. QR 48mm2 4766 0.039 0.0490 9.108

18. RS 48mm2 4666 0.018 0.0490 4.115

19. ST 48mm2 4566 0.063 0.0490 14.095

20. TU 48mm2 4566 0.063 0.0490 14.095

21. UV 48mm2 4278 0.096 0.0490 20.124

22. VW 48mm2 3900 0.063 0.0490 12.039

23. WX 48mm2 3800 0.063 0.0490 11.731

24. XY 48mm2 3775 0.167 0.0490 30.891

25. YZ 48mm2 3515 0.089 0.0490 15.329

26. ZA’ 48mm2 3415 0.065 0.0490 10.877

27. A’B’ 48mm2 3315 0.167 0.0490 27.127

28. B’C’ 48mm2 2552 0.117 0.0490 14.631

29. C’D’ 48mm2 2459 0.415 0.0490 50.004

30. D’E’ 48mm2 2359 0.039 0.0490 4.508

31. E’F’ 48mm2 2289 0.050 0.0490 5.608

32. F’G’ 48mm2 2189 0.085 0.0490 9.117

33. G’H’ 48mm2 2089 0.098 0.0490 10.031

34. H’I’ 48mm2 1889 0.057 0.0490 5.276

35. I’J’ 48mm2 1359 0.125 0.0490 8.524

36. J’K’ 48mm2 1326 0.201 0.0490 13.060

37. K’L’ 48mm2 700 0.254 0.0490 8.712

38. L’M’ 48mm2 600 0.036 0.0490 1.058

Total Voltage drop 963.922

Table 3 Voltage Drop Calculation Data of 11kV Industrial Feeder

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Maximum Demand = 200 Amp.

Demand Factor = √3 x 11 x max. demand

___________________

Total kVA

= √3 x 11 x 200

____________ = 0.487

7829

Actual Voltage drop = Total voltage drop x demand factor

= 963.922 x 0.487 =469.43 units

% voltage drop = Actual voltage drop

_______________________ x 100

11000- Actual voltage drop

% voltage drop = 469.43

____________ x 100 = 4.45%

11000- 469.43

Total circuit length of feeder = 4.317km

On the basis of the above data, graph between the lengths of the various points on feeder versus voltage drop

will be drawn in fig. no. 3.

Fig. 3 Graph between Length of Feeder V/s Voltage Drop

ESTIMATION OF CURRENT IN FEEDER LINES

On the basis of the data of feeder, the calculation of current flowing through the feeder lines can be calculated

as shown in table no. 4.

0

20

40

60

80

100

120

140

160

180

AB

0.1

85

km

CD

0.3

98

km

EF 0

.11

2km

GH

0.1

40

km

IJ 0

.02

6 k

m

KL

0.0

14

km

MN

0.0

35

km

OP

0.0

36

km

QR

0.0

39

km

ST 0

.06

3 k

m

UV

0.0

96

km

WX

0.0

63

km

YZ 0

.08

9km

A'B

' 0.1

67

km

C'D

' 0.4

15

km

E'F'

0.0

50

km

G'H

' 0.0

98

km

I'J' 0

.12

5km

K'L

' 0.2

54

km

Voltage drop

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Current, I = kVA

32

kV length

Section Length in km Voltage Drop

(Volts)

kVA Current in

feeder lines

AB 0.185 70.970 7829 410.92

BC 0.064 24.238 7729 405.67

CD 0.398 148.781 7629 400.43

DE 0.424 155.114 7466 391.87

EF 0.112 40.425 7366 386.62

FG 0.186 66.222 7266 381.37

GH 0.140 49.159 7166 376.12

HI 0.053 18.350 7066 370.88

IJ 0.026 8.875 6966 365.63

JK 0.125 35.929 5866 307.89

KL 0.014 3.955 5766 302.64

LM 0.085 22.766 5466 286.89

MN 0.035 8.860 5166 271.15

NO 0.030 7.447 5066 265.90

OP 0.036 8.760 4966 260.65

PQ 0.034 8.107 4866 255.41

QR 0.039 9.108 4766 250.15

RS 0.018 4.115 4666 244.91

ST 0.063 14.095 4566 239.66

TU 0.063 14.095 4566 239.66

UV 0.096 20.124 4278 224.54

VW 0.063 12.039 3900 204.70

WX 0.063 11.731 3800 199.45

XY 0.167 30.891 3775 198.14

YZ 0.089 15.329 3515 184.49

ZA’ 0.065 10.877 3415 179.24

A’B’ 0.167 27.127 3315 173.99

B’C’ 0.117 14.631 2552 133.95

C’D’ 0.415 50.004 2459 129.07

D’E’ 0.039 4.508 2359 123.82

E’F’ 0.050 5.608 2289 120.14

F’G’ 0.085 9.117 2189 114.89

G’H’ 0.098 10.031 2089 109.65

H’I’ 0.057 5.276 1889 99.15

I’J’ 0.125 8.524 1359 71.33

J’K’ 0.201 13.060 1326 69.60

K’L’ 0.254 8.712 700 36.74

L’M’ 0.036 1.058 600 31.49

4.317 963.922

Table 4 Estimation of current in Feeder Line

From the above calculations, it is assumed that the current estimated on feeder line as reference current value

at power factor of 0.88 (lagging).

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ESTIMATION OF CURRENT AT DIFFERENT POWER FACTOR

On the basis of the current estimation at reference power factor of 0.88 (lagging), estimation of currents at

other power factors, say 0.65 (lag) and unity power factor is also hereby calculated and is as shown in table

no. 5 on the basis of required expression.

Current, I α 1

Cos Ø

Section Current at 0.65

power factor

Current at 0.88 power

factor (reference)

Current at unity power

factor

AB 303.52 410.92 466.95

BC 299.64 405.67 460.99

CD 295.77 400.43 455.03

DE 289.45 391.87 445.30

EF 285.57 386.62 439.34

FG 281.69 381.37 433.37

GH 277.81 376.12 427.41

HI 273.95 370.88 421.45

IJ 270.07 365.63 415.49

JK 227.41 307.89 349.87

KL 223.54 302.64 343.91

LM 211.90 286.89 326.01

MN 200.28 271.15 308.12

NO 196.40 265.90 302.16

OP 192.52 260.65 296.19

PQ 188.65 255.41 290.24

QR 184.77 250.15 284.26

RS 180.90 244.91 278.30

ST 177.02 239.66 272.34

TU 177.02 239.66 272.34

UV 165.85 224.54 255.16

VW 151.20 204.70 232.61

WX 147.32 199.45 226.64

XY 146.35 198.14 225.16

YZ 136.27 184.49 209.64

ZA’ 132.39 179.24 203.68

A’B’ 128.51 173.99 197.71

B’C’ 98.94 133.95 152.21

C’D’ 95.33 129.07 146.67

D’E’ 91.46 123.82 140.70

E’F’ 88.74 120.14 136.52

F’G’ 84.86 114.89 130.55

G’H’ 80.99 109.65 124.60

H’I’ 73.23 99.15 112.67

I’J’ 52.68 71.33 81.06

J’K’ 51.41 69.60 79.09

K’L’ 27.14 36.74 41.75

L’M’ 23.26 31.49 35.78

Table 5 Calculation of Currents in Feeder at Various Power Factors

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6. CALCULATION OF VOLTAGE DROP AT VARIOUS POWER FACTORS AND

TEMPERATURE

As the values of current at various power factors had been determined as per above table. Now voltage

drop can be estimated at various power factors and also at various temperatures of conductors.

6.1 At power factor 0.88 (reference) and at various temperature

Resistance at 200C = 0.3656Ω [14]

Resistance at 650C = 0.4319Ω


On the basis of the above parameters, the voltage drop calculations had been estimated in table no. 6 at

various temperatures i.e. 200C, 65

0C and at 75

0C.

Voltage drop at any temperature = I x Resistance (R) at that temp. Section Current at 0.88pf. Voltage drop at 200C

(reference)

Voltage drop at

650C

Voltage drop at

750C

AB 410.92 150.23 177.47 183.51

BC 405.67 148.31 175.21 181.17

CD 400.43 146.39 172.94 178.83

DE 391.87 143.26 169.24 175.01

EF 386.62 141.34 166.98 172.66

FG 381.37 139.42 164.71 170.32

GH 376.12 137.51 162.44 167.97

HI 370.88 135.59 160.18 165.63

IJ 365.63 133.67 157.91 163.29

JK 307.89 112.56 132.97 137.50

KL 302.64 110.64 130.71 135.16

LM 286.89 104.89 123.90 128.12

MN 271.15 99.13 117.10 121.09

NO 265.90 97.21 114.84 118.75

OP 260.65 95.29 112.57 116.40

PQ 255.41 93.37 110.31 114.06

QR 250.15 91.45 108.04 111.71

RS 244.91 89.54 105.77 109.37

ST 239.66 87.62 103.51 107.03

TU 239.66 87.62 103.51 107.03

UV 224.54 82.09 96.98 100.27

VW 204.70 74.83 88.41 91.42

WX 199.45 72.91 86.14 89.07

XY 198.14 72.44 85.57 88.49

YZ 184.49 67.45 79.68 82.39

ZA’ 179.24 65.53 77.41 80.04

A’B’ 173.99 63.61 75.14 77.70

B’C’ 133.95 48.97 57.85 59.82

C’D’ 129.07 47.18 55.74 57.64

D’E’ 123.82 45.26 53.47 55.29

E’F’ 120.14 43.92 51.89 53.65

F’G’ 114.89 42.00 49.62 51.31

G’H’ 109.65 40.08 47.35 48.97

H’I’ 99.15 36.25 42.82 44.28

I’J’ 71.33 26.07 30.80 31.85

J’K’ 69.60 25.44 30.06 31.08

K’L’ 36.74 13.43 15.86 16.40

L’M’ 31.49 11.51 13.60 14.06

3073.93 3808.84 3938.48

Table 6 Voltage drop Calculations at Power Factor 0.88

The above calculation in table no. 6 is hereby plotted as graph below in fig. no. 4.

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Fig. 4 Graph between Voltage Drop Vs Current at 0.88 Power Factor

6.2 At power factor 0.65 (lagging) and at various temperature






0C and at 75

0C.

Voltage drop at any temperature = I x Resistance (R) at that temp.

0

20

40

60

80

100

120

140

160

180

200

31

.49

69

.6

99

.15

11

4.8

9

12

3.8

2

13

3.9

5

17

9.2

4

19

8.1

4

20

4.7

23

9.6

6

24

4.9

1

25

5.4

1

26

5.9

28

6.8

9

30

7.8

9

37

0.8

8

38

1.3

7

39

1.8

7

40

5.6

7

Voltage drop at 20C

Voltage drop at 65C

Voltage drop at 75C

28 Puneet Chawla


IJEECS

ISSN 2348-117X

Volume 5, Issue 9

September 2016

Section Current at

0.65pf. (lag)

Voltage drop at

200C (reference)

Voltage drop

at 650C

Voltage drop

at 750C

AB 303.52 110.97 131.09 135.55

BC 299.64 109.54 129.41 133.82

CD 295.77 108.13 127.74 132.09

DE 289.45 105.82 125.01 129.26

EF 285.57 104.40 123.33 127.53

FG 281.69 102.98 121.66 125.80

GH 277.81 101.56 119.98 124.07

HI 273.95 100.15 118.32 122.34

IJ 270.07 98.73 116.64 120.61

JK 227.41 83.14 98.21 101.56

KL 223.54 81.72 96.54 99.83

LM 211.90 77.47 91.52 94.63

MN 200.28 73.22 86.50 89.44

NO 196.40 71.80 84.82 87.71

OP 192.52 70.38 83.14 85.97

PQ 188.65 68.97 81.47 84.25

QR 184.77 67.55 79.80 82.51

RS 180.90 66.13 78.13 80.79

ST 177.02 64.71 76.45 79.05

TU 177.02 64.71 76.45 79.05

UV 165.85 60.63 71.63 74.06

VW 151.20 55.27 65.30 67.52

WX 147.32 53.86 63.62 65.79

XY 146.35 53.50 63.20 65.35

YZ 136.27 49.82 58.85 60.85

ZA’ 132.39 48.40 57.17 59.12

A’B’ 128.51 46.98 55.50 57.39

B’C’ 98.94 36.17 42.73 44.18

C’D’ 95.33 34.85 41.17 42.57

D’E’ 91.46 33.43 39.50 40.84

E’F’ 88.74 32.44 38.32 39.63

F’G’ 84.86 31.02 36.65 37.89

G’H’ 80.99 29.61 34.97 36.17

H’I’ 73.23 26.77 31.62 32.70

I’J’ 52.68 19.26 22.75 23.52

J’K’ 51.41 18.79 22.20 22.95

K’L’ 27.14 9.92 11.72 12.12

L’M’ 23.26 8.50 10.04 10.38

2381.3 2813.15 2908.89

Table 7 Voltage Drop Calculations at Power Factor 0.65 (Lag)


29 Puneet Chawla


IJEECS

ISSN 2348-117X

Volume 5, Issue 9

September 2016

Fig. 5 Graph between Voltage Drop Vs Current at 0.65 (Lag) Power Factor

6.3 At power factor Unity and at various temperatures






0C and at 75

0C.

Voltage drop at any temperature = I x Resistance (R) at that temp.

Section Current at unity

pf.

Voltage drop at

200C (reference)

Voltage drop

at 650C

Voltage drop

at 750C

AB 466.95 170.71 201.67 208.53

BC 460.99 168.53 199.10 205.87

CD 455.03 166.35 196.52 203.21

DE 445.30 162.80 192.32 198.87

EF 439.34 160.62 189.75 196.20

FG 433.37 158.44 187.17 193.54

GH 427.41 156.26 184.59 190.88

HI 421.45 154.08 182.02 188.21

IJ 415.49 151.90 179.45 185.55

JK 349.87 127.91 151.10 156.25

KL 343.91 125.73 148.53 153.59

LM 326.01 119.19 140.80 145.59

MN 308.12 112.64 133.07 137.60

NO 302.16 110.47 130.50 134.94

OP 296.19 108.28 127.92 132.27

PQ 290.24 106.11 125.35 129.62

QR 284.26 103.92 122.77 126.95

RS 278.30 101.74 120.19 124.28

ST 272.34 99.56 117.62 121.62

0

20

40

60

80

100

120

140

160

Voltage drop at 20C

Voltage drop at 65C

Voltage drop at 75C

30 Puneet Chawla


IJEECS

ISSN 2348-117X

Volume 5, Issue 9

September 2016

TU 272.34 99.56 117.62 121.62

UV 255.16 93.28 110.20 113.95

VW 232.61 85.04 100.46 103.88

WX 226.64 82.85 97.88 101.21

XY 225.16 82.31 97.24 100.55

YZ 209.64 76.64 90.54 93.62

ZA’ 203.68 74.46 87.96 90.96

A’B’ 197.71 72.28 85.39 88.29

B’C’ 152.21 55.64 65.73 67.97

C’D’ 146.67 53.62 63.34 65.50

D’E’ 140.70 51.44 60.76 62.83

E’F’ 136.52 49.91 58.96 60.96

F’G’ 130.55 47.72 56.38 58.30

G’H’ 124.60 45.55 53.81 55.64

H’I’ 112.67 41.19 48.66 50.31

I’J’ 81.06 29.63 35.00 36.20

J’K’ 79.09 28.91 34.15 35.32

K’L’ 41.75 15.26 18.03 18.64

L’M’ 35.78 13.08 15.45 15.97

3663.80 4328.18 4475.49

Table 8 Voltage Drop Calculations at Unity Power Factor


Fig. 6 Graph between Voltage Drop Vs Current at Unity Power Factor

7. CALCULATION OF DESIGN OF CAPACITOR BANK

0

50

100

150

200

250

35

.78

81

.06

13

0.5

5

14

6.6

7

20

3.6

8

22

6.6

4

27

2.3

4

28

4.2

6

30

2.1

6

34

3.9

1

42

1.4

5

43

9.3

4

46

0.9

9

Voltage drop at 20C

Voltage drop at 65C

Voltage drop at 75C

31 Puneet Chawla


IJEECS

ISSN 2348-117X

Volume 5, Issue 9

September 2016

As per the data issued by the Punjab State Electricity Board of 132kV Subdivision, Abohar, the parameter

available for this particular feeder for all the consumers of different sections as under in table no. 9.

Sr.

No.

Section kVA Km Existing capacity of

Transformer (kVA)

Sanction Load

(kW)

Type of load

connected

Current

(A)

1. AB 7829 0.185 100 10 Domestic 17.39

2. BC 7729 0.064 100 7.5 Domestic 13.04

3. CD 7629 0.398 100 7.5 Domestic 13.04

4. DE 7466 0.424 100 10 Domestic 17.39

5. EF 7366 0.112 100 10 Industrial 18.55

6. FG 7266 0.186 100 10 Industrial 18.55

7. GH 7166 0.140 100 10 Industrial 18.55

8. HI 7066 0.053 100 7.5 Commercial 13.04

9. IJ 6966 0.026 100 7.5 Agricultural 13.91

10. JK 5866 0.125 100 8.625 Industrial 16.00

11. KL 5766 0.014 100 7.5(BHP)

5.595

Agricultural 10.38

12. LM 5466 0.085 100 7.5(BHP)

5.595

Agricultural 10.38

13. MN 5166 0.035 100 8.625 Industrial cum

Agricultural

17.61

14. NO 5066 0.030 100 8.625 Industrial cum

Agricultural

17.61

15. OP 4966 0.036 100 7.5 Commercial 13.04

16. PQ 4866 0.034 100 7.5(BHP)

5.595

Agricultural 10.38

17. QR 4766 0.039 100 7.5(BHP)

5.595

Agricultural 10.38

18. RS 4666 0.018 100 7.5(BHP)

5.595

Agricultural 10.38

19. ST 4566 0.063 100 7.5(BHP)

5.595

Agricultural 10.38

20. TU 4566 0.063 100 7.5(BHP)

5.595

Agricultural 10.38

21. UV 4278 0.096 100 10 Industrial 18.55

22. VW 3900 0.063 100 7.5(BHP)

5.595

Agricultural 10.38

23. WX 3800 0.063 100 7.5(BHP)

5.595

Agricultural 10.38

24. XY 3775 0.167 100 15 Industrial 27.82

25. YZ 3515 0.089 100 7.5 Domestic 13.04

26. ZA’ 3415 0.065 100 7.5 Domestic 13.04

27. A’B’ 3315 0.167 100 7.5(BHP)

5.595

Agricultural 10.38

28. B’C’ 2552 0.117 100 7.5(BHP) Agricultural 10.38

32 Puneet Chawla


IJEECS

ISSN 2348-117X

Volume 5, Issue 9

September 2016

5.595

29. C’D’ 2459 0.415 100 12.5 Industrial 24.84

30. D’E’ 2359 0.039 100 7.5(BHP)

5.595

Agricultural 10.38

31. E’F’ 2289 0.050 100 7.5(BHP)

5.595

Agricultural 10.38

32. F’G’ 2189 0.085 100 7.5(BHP)

5.595

Agricultural 10.38

33. G’H’ 2089 0.098 100 7.5(BHP)

5.595

SP Load 10.38

34. H’I’ 1889 0.057 100 7.5 Domestic 13.04

35. I’J’ 1359 0.125 100 8.865 Industrial 16.00

36. J’K’ 1326 0.201 100 8.865 Industrial 16.00

37. K’L’ 700 0.254 100 8.865 Industrial 16.00

Total 274.55

Table 9 Detail of Load Connected in 11kV Industrial Feeder

In the above table, the sanction load is in kW or in BHP (converted in kW using formula 1HP = 0.746kW.

Current per phase = (sanction power)/ (√3*VL*cos Ø)

Here the voltage on the secondary terminals is considered as 415V and power factor of the feeder is 0.7-0.8

(lagging).

7.1. Calculation of kVAR capacity of Capacitor Bank

As the data obtained and calculated observations, the total load connected in the feeder at different sections is

274.55kW. However, as per the observations made in the table no. 3, kVA is 7829kVA and kVA capacity of

the feeder as assigned by 132kV substation is as referred to table no. 3.

kVA of the feeder = 3 x Max. Demand x voltage rating of feeder = 3 x 200 x 11 = 6600 kVA

As per the maximum capacity of transformer at main substation, the max. kVA capacity is to be 6600kVA but

the delivered kVA at the 1st section of feeder is 7829kVA, which is not meet with the requirement of the

feeding transformer. Thus net kVAR is calculated as under:-

net kVAR capacity of feeder = 𝒌𝑽𝑨𝟐 − 𝒌𝑾𝟐 = 6594.29 kVAR

Thus, as per the above calculations come out in this work, it is proposed that a 1200kVAR, 11kV, 3-Ø

capacitor bank may be installed in the distributed network with 2 x 200kVAR, 1Ø unit per phase.

Thus, capacitance C per unit of the capacitor bank of 6600kVAR, 11kV, 3-Ø

kVAR = kV2 x 2πf x C

or C = 58μfds

This section will have 6 sections in series, giving C/section = 6x58 = 348μfd, kVAR per section = 1100kVAR

and kV/section = 1.83kV.

Hence, from the above calculation, it is observed that a capacitor bank of rating 6600kVAR, 11kV, 3Ø, 50Hz

having capacitance of 58μfds with 6 sections connected in series so that the required voltage may not exceed

2kV.

8. CONCLUSION

33 Puneet Chawla


IJEECS

ISSN 2348-117X

Volume 5, Issue 9

September 2016

From the above calculations and study, it has been observed that the existing conductor size of 48mm2

(RACCOON) can be replaced by use of 55mm2 (CAT) for reduction of voltage drop in feeder, due to its better

current carrying capacity of 305A in comparison of 270A of 48mm2 conductor and same linear coefficient of

temperature rise and modulus of elasticity. But the weight of 55mm2 conductor is 19.3mm

2 increased from

existing 91.97mm2 to 111.3 mm

2, which can be supported by the existing structures installed in the feeder

area, as net increase in the area of the proposed conductor is within the limits as per norms. In the 11kV

feeder, it is proposed by the State Electricity Board that some sections of the feeder may be augmented by

ACSR conductors of size 80mm2, bur as per calculations; it is proposed that 55mm

2 conductor may be used

without much change in the existing structures. From the above calculation, it is observed that a capacitor

bank of rating 6600kVAR, 11kV, 3Ø, 50Hz having capacitance of 58μfds with 6 sections connected in series

so that the required voltage may not exceed 2kV.

9. REFERENCES

[1] Ministry of Power and Energy, Govt. of India, www.powermin.nic.in.

[2] Punjab State Power Corporation Ltd., www.pspcl.gov.in.

[3] Ritula Thakur & Puneet Chawla, “Design of Urban Distribution Feeders For Voltage Profile Improvement &

Distribution Losses Reduction”, International Journal of Recent Technologies in Mechanical & Electrical

Engineering, Volume 2, Issue 8, August, 2015.

[4] Soloman Nunoo, Joesph C. Attachie and Franklin N. Duah, “An Investigation into the Causes and Effects of Voltage

drops on 11KV Feeder”, Canadian Journal of Electrical and Electronics Engineering, Vol. 3, January, 2012.

[5] Vujosevic, L. Spahic E. and Rakocevic D., “One Method for the Estimation of voltage drop in Distribution System”,

http://www.docstoc.com/document/ education, March, 2011.

[6] C.G. Carter-Brown and C.T. Gaunt, “Model for the apportionment of the total voltage drop in Combined Medium

and Low Voltage Distribution Feeders”, Journal of South African Institute of Electrical Engineers, Vol. 97(1),

March, 2006.

[7] C.G. Carter-Brown, “Voltage drop apportionment in Eskom’s distribution networks”, Masters dissertation,

University of Cape Town South Africa, pp. 28-33, 50,52,55,60, 2002.

[8] C.G. Carter-Brown, “Optimal voltage regulation limits and voltage drop apportionment in distribution systems”, 11th

Southern African Universities Power Engineering Conference (SAUPEC, 2002) pp. 318-322, Jan/Feb., 2002.

[9] Sarang Pande and Prof. J. G. Ghodekar, “Computation of Technical Power Loss of Feeders and Transformers in

Distribution System using Load Factor and Load Loss Factor”, International Journal of Multidisciplinary Sciences

and Engineering, Vol. 3. No. 6, June, 2012.

[10] J. J. Grainger, S.H. Lee, A.M. Byrd and K,N. Clinard, “ Proper Placement of capacitors for Losses reduction on

distribution primary feeders”, in Proceedings, American :Power Conference, No. 42, pp. 593-603, 1980.

[11] Handbook of ABB, “Technical Application Papers No. 8, Power factor Correction and harmonic filtering in

electrical plants”, ABB Sace, Via Baloni, Italy, December, 2010.

[12] Manual of Nokian Capacitors, “Power Factor correction”, Kaapelikatu, Tampere, Finland, November, 2002.

[13] Data obtained from 132kV Subdivision, Abohar of Punjab State Power Cooperation Ltd., Abohar Subdivision.

[14] M.V. Deshpande, “Electrical Power System Design” Page 350, Table A2: Aluminium Conductor Steel Reinforced

(Based on IS: 398[1961]), Tata McGraw Hill Publishing Company Limited, Edition 2006.

http://www.powermin.nic.in/

http://www.pspcl.gov.in/

http://www.docstoc.com/document/%20education

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Performance Analysis of 11KV Industrial Distribution ... · Performance Analysis of 11KV Industrial Distribution Feeder ... Capacitor banks and voltage regulators are installed to